Theres a few threads about this, i´ve also been looking for some real cases of this retrofit, but all i could find was just a few videos from some asian people and a russian guy explaining the retrofit (I dont speak nor read any russian haha).
Bimmer retrofit used to sell this kit in 2015 for around 1400 usd....
http://www.bimmerretrofit.com/store/...product_id=117
besides you will need to cut and trim several dashboard pieces to make it work
http://www.e90post.com/forums/showthread.php?t=1203471